The use of adhesive and/or resinous materials in cosmetic compositions is well known in the art, especially in the field of hair setting or styling aids and also skin-care products.
EP-A-240350 for example discloses the use of specific silicone polymers dissolved in a volatile carrier material for giving improved style retention to hair.
In FR-A-1102563 (published 1955) for instance there is disclosed an elastic cosmetic fixative for hair and moustaches, consisting of an elastomer dissolved in a hydrocarbon, especially Vaseline.RTM..
A feature common to these known cosmetic products is the use of a solvent or carrier for the adhesive and/or resinous material. In some cases, especially skin care products, such a solvent or carrier is generally necessary in order to provide a product which is practically and aesthetically acceptable. In the field of hair care compositions, which are generally aqueous based, since the known adhesive and/or resinous materials are generally water-insoluble, a solvent or carrier has hitherto been necessary in order to successfully incorporate the material in the composition in a stable emulsified form.
The need to use such solvents or carriers brings with it several disadvantages. For example:
(a) products obtained through the use of such solvents or carriers are prone to significant thinning (i.e. low viscosity), thereby making it necessary to use a thickening ingredient to provide a product having a viscosity which is commercially and aesthetically acceptable; PA1 (b) the need to use a solvent or carrier means that product manufacture requires at least one extra processing step which increases manufacturing time and cost; PA1 (c) having to use a solvent or carrier means yet another formulation ingredient which increases the overall cost of raw materials; PA1 (d) the known solvents or carriers, being generally volatile organic liquids, for safety reasons require strict handling and processing conditions, e.g. flame-proof equipment must be used. This contributes significantly to the overall cost and complexity of the manufacturing processes; PA1 (e) volatile organic solvents or carriers generally act as foam suppressors and therefore impair the foamability and ease of spreading, e.g. on hair, of products, especially shampoos, containing them.
More recently, in our copending European patent application EP-A-0 498 119 there are disclosed hair styling compositions for imparting body and/or stylability to hair comprising, in addition to at least one of surfactant, conditioning agent and water or other volatile solvent, a per-alk(en)yl hydrocarbon material, e.g. polyisobutylene. The particularly preferred per-alk(en)yl hydrocarbon-containing compositions, and those actually exemplified therein, utilise an aforementioned solvent or carrier, e.g. a low molecular weight hydrocarbon, to dissolve or disperse the per-alk(en)yl hydrocarbon hair styling agent which preferably has a relatively high molecular weight. Therefore, even this latest proposal faces the above mentioned problems characteristic of the prior art cosmetic compositions containing adhesive and/or resinous materials.